Clearing the air

A THICK, HAZY, BROWN CLOUD
of pollution often hangs over all of South Asia, affecting
not only billions of residents' health, but also the climate in which they live. The cloud is comprised of a range of air pollutants, including microscopic particles from biomass fuels like cow dung, and fossil fuels. The particles contain black carbon, sulfates and nitrates, which affect
affect sunlight and rainfall in the region, and possibly agriculture and fresh water supplies.

Through an ongoing National Oceanic and Atmospheric Administration and United Nations Environment Programme-funded initiative, Associate Professor
Jamie Schauer
is part of an international team studying the brown cloud's effect on regional and global climate change, water balance, agriculture and public health.

He and postdoctoral researcher Glynis Lough, and PhD students Betsy Stone and Rachelle Duvall are helping to establish observatories in the Maldives Islands, Midway Island, Nepal, Korea and at Trinidad Head in the U.S. state of Oregon. At each station, they train local personnel to collect air samples, and then Schauer and his team analyze the samples' chemical composition and track the pollutants' sources.
With the data, researchers participating in the initiative (dubbed Project Atmospheric Brown Cloud, or ABC) are developing models
to study near- and long-term changes in climate and brown-cloud composition.

Polymer grid technology a boon for bridges

WHEN THE LONG-AWAITED
Highway 151 bypass around Fond du Lac, Wisconsin, opens
later this year, vehicles traveling northbound will cross DeNeveu Creek on a bridge like no other in the country. Externally, the bridge looks identical to its adjacent twin.
However, internally, the concrete deck is reinforced with a novel fiber-reinforced polymer (FRP) grid system that could replace conventional epoxy-coated reinforcing bars (rebars) inside future bridges.

Professor
Larry Bank,
Associate Professor
Mike Oliva
and graduate students David Jacobson and Mack Conachen developed the system, which boasts several advantages over rust-prone steel rebars. The FRP material won't corrode, doubling the lifetime of bridge decks from 30 or 40 years to nearly 75 years.

In addition, steel rebars are long rods, which workers then have to tie together and position. But
Bank's
group designed prefabricated, three-dimensional FRP grids that cranes can lay rapidly into place, eliminating weeks of labor-intensive work and speeding up bridge construction or deck replacement. The grid system could be cost-competitive with current techniques, says
Bank.

Thanks to funding from a Federal Highway Administration program called Innovative Bridge Research & Construction, and cooperation from partners at the Wisconsin Department of Transportation, the Wisconsin bridge was the first of a kind. This summer, workers constructed a second bridge using a variation of the grid system in Greene County, Missouri — and Bank's group is studying ways to improve the technology.

Calling our bluffs:Characterizing Lake Superior shore erosion

LAKE HOMES
often are sited too close to the edge of
a bluff, and owners don't realize they are living in a
highly reactive environment, says Professor
Tuncer Edil.
To help local governments plan and manage shoreline
development, he and Assistant Professor
Chin H. Wu,
Geology and Geophysics Professor
David Mickelson,
and Research Assistant
Mike Swenson
characterized the state of erosion along the Wisconsin shoreline of Lake Superior.

The group estimated how much bluff recession will
occur within the next 50 years if lake levels change — for
example, as a result of global warming. The researchers
surveyed the lake's entire shoreline to characterize its
current state of erosion, then compared those results with
historical air photos to measure how far its bluffs have
retreated during the past 30 years. During large storms,
they also measured how far waves rushed onto the lake's
beaches and compared the results with historical wave data
to determine how much wave energy reaches bluffs with
different shoreline characteristics. Using historical bluffrecession
measurements, they showed that bluff recession
is related to wave-energy measurements.

The data enables the researchers to predict erosion.
With individual studies of the relationships between wave
energy and erosion, the research could apply to other
large water-body erosion situations, says Edil. Ultimately,
it will enable local governments to establish shoreline
zoning ordinances — and the knowledge will help builders
determine safe setback distances for lake homes.

“Super” material makes great green batteries

USING AN UNUSUAL COMPOUND
called iron-VI, or “super iron,” Professor
Marc Anderson
and
doctoral candidate Ken Walz (also a faculty member at the Madison Area Technical College)
are designing environmentally friendly batteries that deliver more power but weigh less.

Traditional alkaline batteries contain zinc and magnesium dioxide and generate power via oxidation and reduction reactions. On the anode side, the zinc loses two electrons. They travel through an electrical circuit, providing power, and return to the cathode to combine with the magnesium dioxide, which can accept only one electron at a time. The cathode reaction must occur twice for every reaction in the anode, limiting the battery's performance.

With funding from a variety of sources, including the United States government and the National Science Foundation, Anderson and Walz are developing batteries that replace the magnesium dioxide with the iron-VI. In theory, the iron-VI can handle three electrons at a time, speeding up the reaction time and reducing the battery's weight. And when the zinc is consumed and the battery dies, all that's left is iron-III, or rust.

The two are developing prototypes of “button” batteries (those that power devices such as wristwatches). In the future, they hope to scale up to larger batteries — the kind parents buy in abundance to power their kids' toys.

Copyright 2005 The Board of Regents of the University of Wisconsin System
Content: perspective@engr.wisc.eduWeb: COE web servicesDate last modified: 19-Jan-2006.
Date created: 25-Oct-2005.
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